Rewrite ${((3^{8})(5^{-6}))^{7}}$ in the form ${3^n \times 5^m}$.
Solution: ${ ((3^{8})(5^{-6}))^{7} = (3^{(8)(7)})(5^{(-6)(7)})} $ ${\hphantom{ ((3^{8})(5^{-6}))^{7}} = 3^{56} \times 5^{-42}} $